Disappearing Act: Could Saturn’s Rings Eventually Vanish?

Jon Hartley 12/29/2018

Saturn has always been one of the most distinctive planets in the solar system because of its amazing rings, making it – after Earth and Mars, of course – perhaps the most famous planet in the Milky Way, and certainly one of the easiest to remember in grade school science class. However, the rings that have made the planet so notable aren’t likely to be around forever, according to scientists.

Disappearing Act: Could Saturn’s Rings Eventually Vanish?

In fact, Saturn’s rings are likely to be gone as soon as 100 million years from now, which is an epic time frame compared to our modest lifespans but a relative blink of an eye in cosmological terms.

It may be surprising to learn that Saturn may not have always had its rings to begin with. They actually may have formed about 100 million years ago due to colliding moons in orbit around the planet, according to scientists. Again, while this would seem like a long time to us, this would mean that as recently as when giant dinosaurs roamed the Earth, Saturn was ring-less.

Why are its rings in danger of disappearing in the (pretty distant) future? Because Saturn’s gravity and magnetic field are causing what researcher James O’Donoghue calls “ring rain,” which causes the rings to decay over time. What’s more, O’Donoghue speculates that perhaps other planets, such as Jupiter and Neptune, also once had giant rings.

Disappearing Act: Could Saturn’s Rings Eventually Vanish?

“We are lucky to be around to see Saturn’s ring system, which appears to be in the middle of its lifetime,” O’Donoghue said. “However, if rings are temporary, perhaps we just missed out on seeing giant ring systems of Jupiter, Uranus, and Neptune, which have only thin ringlets today.”

Although you can’t tell from watching Saturn through a telescope, Saturn’s rings are constantly balancing between the gravitational pull of Saturn and the orbital pull that is trying to bring them out into space.